Replace source diagram legend and note “CAUTION – The date of survey …“ with the following legend:

[magenta] Surveying 1932–1940, lead-line. Incomplete old surveys. Depth anomalies may be expected. Great care shoud therefore been exercised when navigating in these waters.[green] Surveying 1981–2003, single-beam echosounder. Uncharted features hazardous to surface navigation are not expected, but may exist.[blue] Surveying 1981–2003, multi-beam echosounder. All significant seafloor features detected.